Insulated sub-surface liquid line direct expansion heat exchange unit with liquid trap

Abstract

A direct expansion geothermal heat exchange unit, which can be placed in sub-surface ground and/or water, consisting of at least one insulated refrigerant liquid/fluid line, with a liquid trap at the bottom of the liquid/fluid line, with at least one un-insulated refrigerant vapor/fluid line operatively connected to the insulated liquid/fluid line at a point above the liquid trap, where the un-insulated vapor/fluid line is in thermal contact with its adjacent sub-surface surrounding elements by means of a heat conductive fill material inserted as necessary to fill any void space, in any borehole or excavated area, between the vapor/fluid line and its respective adjacent sub-surface surroundings.

1. A geothermal heat exchange unit comprising:
 at least one insulated refrigerant fluid transport line having an inner diameter, with at least a lower portion and lower segment of the at least one insulated refrigerant fluid transport line positioned in a sub-surface location;  
 a first un-insulated fluid transport line having a distal end operatively coupled to the lower segment of the least one insulated fluid transport line in the sub-surface location, with at least the lower portion of the first un-insulated fluid transport line in thermal contact with sub-surface material in the sub-surface location;  
 wherein the first un-insulated fluid transport line has an inner diameter that is larger than the inner diameter of the at least one insulated refrigerant fluid transport line;  
 layer of thermal insulation surrounding the lower portion of the at least one insulated refrigerant fluid transport line; and  
 wherein the layer of thermal insulation is in physical contact with the sub-surface material.  
 
     
     
       2. A geothermal heat exchange unit comprising:
 at least one insulated refrigerant fluid transport line having an inner diameter, with at least a lower portion and lower segment of the at least one insulated refrigerant fluid transport line positioned in a sub-surface location;  
 a first un-insulated fluid transport line having a distal end operatively coupled to the lower segment of the least one insulated fluid transport line in the sub-surface location, with at least the lower portion of the first un-insulated fluid transport line in thermal contact with sub-surface material in the sub-surface location;  
 wherein the first un-insulated fluid transport line has an inner diameter that is larger than the inner diameter of the at least one insulated refrigerant fluid transport line; and  
 wherein the lower segment of the at least one insulated fluid transport line comprises a first liquid trap operatively connected to the distal end of the first un-insulated fluid transport line at a point within the sub-surface location that is above the first liquid trap.  
 
     
     
       3. The geothermal heat exchange unit of either  claim 1  or  claim 2  where the first un-insulated fluid transport line extends at least seventy-five percent of the length and the depth of the insulated fluid transport line within the sub-surface location. 
     
     
       4. The geothermal heat exchange unit of either of  claim 1  or  claim 2  further comprising a plurality of un-insulated fluid transport lines each having respective distal ends operatively coupled to the at least one un-insulated fluid transport line by a second fluid trap. 
     
     
       5. The geothermal heat exchange unit of  claim 1  wherein the inner diameter of the at least one insulated refrigerant fluid transport line and the inner diameter of the first un-insulated fluid transport line are adapted for operative connection to a closed-loop direct expansion heat pump system. 
     
     
       6. The geothermal heat exchange unit of either  claim 1  or  claim 2  wherein the first un-insulated fluid transport line comprises a spiral tube positioned around the at least one insulated fluid transport line. 
     
     
       7. The geothermal heat exchange unit of  claim 2  wherein the first liquid trap comprises a U-shaped bend in the lower segment of the least one insulated fluid transport line. 
     
     
       8. A geothermal heat exchange arrangement comprising:
 a sub-surface borehole;  
 an insulated refrigerant liquid/fluid transport line extending vertically within the borehole;  
 an un-insulated refrigerant vapor/fluid transport line extending vertically within the borehole proximate the insulated refrigerant liquid/fluid transport line;  
 the insulated refrigerant liquid/fluid transport line having an inner diameter that is smaller than an inner diameter of the un-insulated refrigerant vapor/fluid transport line;  
 the insulated refrigerant liquid/fluid transport line further comprising a U-shaped liquid trap connecting the insulated refrigerant liquid/fluid transport line to the un-insulated refrigerant vapor/fluid transport line proximate a bottom end of the borehole; and  
 heat conductive fill material in thermal contact with the un-insulated refrigerant vapor/fluid transport line.  
 
     
     
       9. The geothermal heat exchange arrangement of  claim 8  wherein the un-insulated refrigerant vapor/fluid transport line comprises a plurality of vertical tubes. 
     
     
       10. The geothermal heat exchange arrangement of  claim 8  wherein the un-insulated refrigerant vapor/fluid transport line comprises a spiral tube. 
     
     
       11. A geothermal heat exchange arrangement comprising:
 an insulated refrigerant liquid/fluid transport line extending substantially horizontally within a sub-surface location;  
 an un-insulated refrigerant vapor/fluid transport line extending substantially horizontally within the sub-surface location proximate the insulated refrigerant liquid/fluid transport line;  
 the insulated refrigerant liquid/fluid transport line having an inner diameter that is smaller than an inner diameter of the un-insulated refrigerant vapor/fluid transport line;  
 the insulated refrigerant liquid/fluid transport line further comprising a vertically-oriented liquid trap connecting a distal end of the insulated refrigerant liquid/fluid transport line to a distal end of the un-insulated refrigerant vapor/fluid transport line; and heat conductive sub-surface material in thermal contact with the un-insulated refrigerant vapor/fluid transport line.  
 
     
     
       12. The geothermal heat exchange arrangement of  claim 11  wherein the un-insulated refrigerant vapor/fluid transport line comprises a plurality of horizontal tubes. 
     
     
       13. The geothermal heat exchange arrangement of  claim 11  wherein the un-insulated refrigerant vapor/fluid transport line comprises a spiral tube.